80 research outputs found
Mitochondria DNA mutations cause sex-dependent development of hypertension and alterations in cardiovascular function
Aging is associated with conduit artery stiffening that is a risk factor for and can precede hypertension and ventricular dysfunction. Increases in mitochondria DNA (mtDNA) frequency have been correlated with aging. Mice with a mutation in the encoding domain (D257A) of a proof-reading deficient version of mtDNA polymerase-γ (POLG) have musculoskeletal features of premature aging and a shortened lifespan. However, few studies using these mice have investigated the effects of mtDNA mutations on cardiovascular function. We hypothesized that the proof-reading deficient mtDNA POLG leads to arterial stiffening, hypertension, and ventricular hypertrophy. Ten to twelve month-old D257A mice (n=13) and age- and sex-matched wild-type controls (n=13) were catheterized for hemodynamic and ventricular function measurements. Left common carotid arteries (LCCA) were harvested for mechanical tests followed by histology. Male D257A mice had pulmonary and systemic hypertension, arterial stiffening, larger LCCA diameter (701±45 vs. 597±60 μm), shorter LCCA axial length (8.96±0.56 vs. 10.10±0.80 mm), and reduced hematocrit (29.1±6.1 vs. 41.3±8.1; all p<0.05). Male and female D257A mice had biventricular hypertrophy (p<0.05). Female D257A mice did not have significant increases in pressure or arterial stiffening, suggesting that the mechanisms of hypertension or arterial stiffening from mtDNA mutations differ based on sex. Our results lend insight into the mechanisms of age-related cardiovascular disease and may point to novel treatment strategies to address cardiovascular mortality in the elderly
Plasticity of host selection by malaria vectors of Papua New Guinea
Background
Host selection is an important determinant of vectorial capacity because malaria transmission increases when mosquitoes feed more on humans than non-humans. Host selection also affects the outcome of long-lasting insecticidal nets (LLIN). Despite the recent nationwide implementation of LLIN-based malaria control program in Papua New Guinea (PNG), little is known about the host selection of the local Anopheles vectors. This study investigated the host selection of Anopheles vectors in PNG.
Methods
Blood-engorged mosquitoes were sampled using the barrier screen method and blood meals analyzed for vertebrate host source with PCR-amplification of the mitochondrial cytochrome b gene. Abundance of common hosts was estimated in surveys. The test of homogeneity of proportions and the Manly resource selection ratio were used to determine if hosts were selected in proportion to their abundance.
Results
Two thousand four hundred and forty blood fed Anopheles females of seven species were sampled from five villages in Madang, PNG. Of 2,142 samples tested, 2,061 (96.2%) yielded a definitive host source; all were human, pig, or dog. Hosts were not selected in proportion to their abundance, but rather were under-selected or over-selected by the mosquitoes. Four species, Anopheles farauti (sensu stricto) (s.s.), Anopheles punctulatus (s.s.), Anopheles farauti no. 4 and Anopheles longirostris, over-selected humans in villages with low LLIN usage, but over-selected pigs in villages with high LLIN usage. Anopheles koliensis consistently over-selected humans despite high LLIN usage, and Anopheles bancroftii over-selected pigs.
Conclusions
The plasticity of host selection of an Anopheles species depends on its opportunistic, anthropophilic or zoophilic behavior, and on the extent of host availability and LLIN usage where the mosquitoes forage for hosts. The high anthropophily of An. koliensis increases the likelihood of contacting the LLIN inside houses. This allows its population size to be reduced to levels insufficient to support transmission. In contrast, by feeding on alternative hosts the likelihood of the opportunistic species to contact LLIN is lower, making them difficult to control. By maintaining high population size, the proportion that feed on humans outdoors can sustain residual transmission despite high LLIN usage in the village
Ontogenetic shifts in trait-mediated mechanisms of plant community assembly
Identifying the processes that maintain highly diverse plant communities remains a central goal in ecology. Species variation in growth and survival rates across ontogeny, represented by tree size classes and life history stage-specific niche partitioning, are potentially important mechanisms for promoting forest diversity. However, the role of ontogeny in mediating competitive dynamics and promoting functional diversity is not well understood, particular in high-diversity systems such as tropical forests. The interaction between interspecific functional trait variation and ontogenetic shifts in competitive dynamics may yield insights into the ecophysiological mechanisms promoting community diversity. We investigated how functional trait (seed size, maximum height, SLA, leaf N, and wood density) associations with growth, survival, and response to competing neighbors differ among seedlings and two size classes of trees in a subtropical rain forest in Puerto Rico. We used a hierarchical Bayes model of diameter growth and survival to infer trait relationships with ontogenetic change in competitive dynamics. Traits were more strongly associated with average growth and survival than with neighborhood interactions, and were highly consistent across ontogeny for most traits. The associations between trait values and tree responses to crowding by neighbors showed significant shifts as trees grew. Large trees exhibited greater growth as the difference in species trait values among neighbors increased, suggesting trait-associated niche partitioning was important for the largest size class. Our results identify potential axes of niche partitioning and performance-equalizing functional trade-offs across ontogeny, promoting species coexistence in this diverse forest community
Human trafficking and violence: Findings from the largest global dataset of trafficking survivors.
BACKGROUND: Human trafficking is a recognized human rights violation, and a public health and global development issue. Violence is often a hallmark of human trafficking. This study aims to describe documented cases of violence amongst persons identified as victims of trafficking, examine associated factors throughout the trafficking cycle and explore prevalence of abuse in different labour sectors. METHODS AND FINDINGS: The IOM Victim of Trafficking Database (VoTD) is the largest database on human trafficking worldwide. This database is actively used across all IOM regional and country missions as a standardized anti-trafficking case-management tool. This analysis utilized the cases of 10,369 trafficked victims in the VoTD who had information on violence. RESULTS: The prevalence of reported violence during human trafficking included: 54% physical and/or sexual violence; 50% physical violence; and 15% sexual violence, with 25% of women reporting sexual violence. Experiences of physical and sexual violence amongst trafficked victims were significantly higher amongst women and girls (AOR 2.48 (CI: 2.01,3.06)), individuals in sexual exploitation (AOR 2.08 (CI: 1.22,3.54)) and those experiencing other forms of abuse and deprivation, such as threats (AOR 2.89 (CI: 2.10,3.98)) and forced use of alcohol and drugs (AOR 2.37 (CI: 1.08,5.21)). Abuse was significantly lower amongst individuals trafficked internationally (AOR 0.36 (CI: 0.19,0.68)) and those using forged documents (AOR 0.64 (CI: 0.44,0.93)). Violence was frequently associated with trafficking into manufacturing, agriculture and begging (> 55%). CONCLUSIONS: An analysis of the world's largest data set on trafficking victims indicates that violence is indeed prevalent and gendered. While these results show that trafficking-related violence is common, findings suggest there are patterns of violence, which highlights that post-trafficking services must address the specific support needs of different survivors
Labor Recruitment and Human Trafficking: Analysis of a Global Trafficking Survivor Database
Over the past decade, third-party labor recruiters who facilitate employment for migrant workers across low- and middle-income countries have often been considered by the counter-trafficking community as one of the main entry points into human trafficking. In response, anti-trafficking prevention programs have increasingly focused on addressing exploitative recruitment in migrants’ origin countries. Such programs may advocate for increased regulation of migration, greater enforcement actions against unlicensed recruiters, stricter ethical codes of conduct for recruiters and employers, and more pre-departure information about recruitment for migrants. Yet, there remains limited research about the relationship between prospective migrants, recruiters, and human trafficking, and the relative importance of third-party recruitment in the trafficking process. This Research Note draws on the world's largest database of individual victims of trafficking cases, the International Organization for Migration's (IOM) Global Victim of Trafficking Database (VoTD), to examine the role and characteristics of recruitment of trafficked victims. The VoTD contains information on nearly 50,000 trafficking victims who were registered for assistance from 2002 to June 2018. Our analysis shows that 94 percent of trafficked victims were recruited, in a broad sense (i.e., not only by third-party intermediaries). Additionally, the data presented here suggest that the relationship between recruitment and trafficking is complex and that forced labor is embedded within the wider structural issues around low-wage labor migration that lead to exploitative work conditions. Interventions to address human trafficking will benefit from strategies that target systemic issues constraining or harming low-wage labor. Further, these findings highlight the value of large-scale administrative datasets in migration research. </jats:p
Evaluation of three PCR-based diagnostic assays for detecting mixed Plasmodium infection
<p>Abstract</p> <p>Background</p> <p>One of the most commonly used molecular test for malaria diagnosis is the polymerase chain reaction (PCR)-based amplification of the 18S ribosomal DNA (rDNA) gene. Published diagnostic assays based on the 18S gene include the "gold standard" nested assay, semi-nested multiplex assay, and one tube multiplex assay. To our knowledge, no one has reported whether the two multiplex methods are better at detecting mixed <it>Plasmodium </it>infections compared to the nested assay using known quantities of DNA in experimentally mixed cocktails.</p> <p>Findings</p> <p>Here we evaluated three PCR assays (nested, semi-nested multiplex, and one-tube multiplex) for the simultaneous detection of human malaria parasites using experimentally mixed cocktails of known quantities of laboratory derived DNA. All three assays detected individual species with high sensitivity and specificity when DNA was from any one single species; however, experimentally mixed DNA cocktails with all four species present were correctly identified most consistently with the nested method. The other two methods failed to consistently identify all four species correctly, especially at lower concentrations of DNA -subclinical levels of malaria (DNA equivalent to or less than 10 parasites per microliter).</p> <p>Conclusions</p> <p>The nested PCR method remains the method of choice for the detection of mixed malaria infections and especially of sub-clinical infections. Further optimization and/or new molecular gene targets may improve the success rate of detecting multiple parasite species simultaneously using traditional PCR assays.</p
Bringing People Back into Public Health Data: Community Feedback on a Set of Visualization Tools - Summary Report
This course-based study is a product of the University of Denver’s Spring 2022 The Social Determination of Health (ANTH 2424) class. The study aimed to understand how well a set of public health visualization tools tells the data stories about people in Colorado, and about important public health problems. For this, a team of almost sixty undergraduate students taking the class, coordinated by three graduate teaching assistants, and directed by the course instructor interviewed a total of fifty-six people from Colorado, qualitatively analyzed those interviews, and wrote reports that draw conclusions and recommendations
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